Major Forms of Cellular Adaptation Flashcards
Review of atrophy, hypertrophy, hyperplasia, metaplasia, and dysplasia
Cells can adapt through modulation of their…
size, shape, metabolism, and behavior
What are five major forms of cellular adaptation?
- Atrophy
- Hypertrophy
- Hyperplasia
- Metaplasia
- Dysplasia
What is atrophy?
Shrinkage of a cell or organ due to loss of organelles
An adaptation to diminish need or resources for cell activity
What is physiological atrophy?
A normal loss of endocrine stimulation
ex. lack of use (reversible)
What is pathological atrophy?
Diminished blood supply, inadequate nutrition, loss of innervation, abnormal loss of endocrine stimulation, decreased workload
ex. paraplegia (atrophy to limbs)
What is hypertrophy?
An increase in cell size and functional capacity
Increase in production and number of intracellular organelles (hypertrophy) will mean what for metabolic demands?
Increased metabolic demands on the cell/hormonal stimulation
What is physiological hypertrophy?
Increased functional demand
ex. working out and building muscle
What is goiter?
A pathological hypertrophy enlarging the thyroid gland
A hormone secreting tumor will mean what for an endocrine gland?
Hyperactivity
High blood pressure can lead to heart hypertrophy. What kind of hypertrophy is this?
Pathological
Excessive abnormal demands on an organ will lead to which adaptation?
Pathological hypertrophy
What is hyperplasia?
Increase in the size of an organ or tissue due to an increase in the number of cells
What are examples of physiological hyperplasia?
Hormonal stimulation in lactating breast, increase in RBCs at high altitude
What are examples of pathological hyperplasia?
Endometriosis, psoriasis, liver regeneration following damage
What is metaplasia?
A change where one terminally differentiated cell type is replaced by another terminally differentiated cell type
What is metaplasia a response to?
Persistent injury/irritation
Commonly, glandular epithelium is replaced by…
squamous epithelium
Describe Barret esophagus
Simple columnar metaplasia creeping up esophagus
Give two examples of squamous metaplasia
Bronchus, bladder
What is myositis ossificans?
After injury, soft tissue (muscle) will behave like bone showing bright on a radiograph
What is dysplasia?
Disordered growth and maturation of the cellular components of a tissue
Loss of uniformity of cells as well as loss in architectural orientation describes what adaptation?
Dysplasia
Dysplasia is a response to…
persistent injurious influence; may regress
